<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="app">
      <h1>{{ msg }}</h1>
      <button @click="reverseMsg">翻转世界</button>
    </div>

    <script src="./vue.js"></script>

    <script>
      new Vue({
        el: '#app',
        data: {
          msg: 'Hello World.',
        },
        methods: {
          reverseMsg() {
            // 1. 将msg转成数组
            // 2. 再翻转
            // 3. 将数组转成字符串
            this.msg = this.msg.split('').reverse().join('');
          },
        },
      });
    </script>
  </body>
</html>
